High performance polyethylene (HPPE) is widely used in medical devices such as sutures, cables, meshes etc, many of which are used in minimally invasive surgery. There is hence a desire to verify the position of the medical device in applications where visual inspection is not possible during or after surgery. X-rays are commonly used for visualization of other types of medical devices comprising metal parts, however, HPPE absorbs substantially the same amount of x-rays as soft human tissue and HPPE members are traditionally hence not visible using x-ray visualization techniques. Various approaches have been attempted to introduce radiopacity into medical devices comprising HPPE including impregnation with solutions of radiopaque salts such as BaSO4 followed by drying, incorporation of a metal wire in the construction, coating the medical device with a radiopaque coating, and incorporating radiopaque particles of BaSO4 into the yarn. However, these technique leads to one or more of the risk of leaching, reduced flexibility of the yarn, and/or reduced specific strength.
WO 2009/115291 discloses an implant, which may comprise UHMWPE yarn. It is disclosed that the implant also may comprise tantalum metal fiber.